Synthetic tanning material



METED "STATES PATENT oFFlcE SYNTHETIC TANNIN G MATERIAL William F. Hester, Drexel Hill, Harry B. Rater-ink, Philadelphia, and Ian G. Somerville, Fox Chase. Pa, assignors to Bohm & Haas Company, Philadelphia, Pa.

No Drawing. Application October 10, 1932,

1 Serial No. 637,100

13 Claims. (UL 280-4) This invention relates to new synthetic tanning matic sulphonic acids in a medium of sulphuric materials. acid or non-sulphonating strength, the subsc- It is well known that sulphonic acids of aroquent formaldehyde condensation proceeds very matic hydrocarbons may be condensed by means smoothly in the absence of any nitrogenous ma- 8 of aldehydes to produce substances which will terial, to yield products whose tanning properties precipitate gelatin, and convert hides or skins are far superior to those made by corresponding into leather. Similar products may be secured by reactions without salicylic acid present. condensing aromatic hydrocarbons first with The invention is illustrated in the examples aldehydes, and rendering the resinous materials below which are representative of various types it) so obtained water soluble by sulphonation. These of materials which can be used in this reaction. 10 reactions have been carried out starting with It is obvious however that other extensions will many varieties of organic compounds, such as readily suggest themselves to one skilled in the naphthalene, tetrahydronaphthalene, anthraart, and the invention is not confined to the excene, phenanthrene, carbazole, phenol, cresol, amples given. 05 course, the method 0! sulpho- 5 naphthol, while various aldehydes have also been nation of the aromatic hydrocarbon is immateemployed, such as formaldehyde, acetaldehyde, rial since it makes no diii'erence in applicants iurfuraldehyde, benzaldehyde. As a modification process whether sulphuric acid or some other sulof these two types of reaction it has also been prophonation agent has been used such as oleuxn or posed to condense a sulphonated aromatic hydrochlorosulphonic acid, etc.

at carbon with a nonsulpho'nated nucleus by means Exam l8 1 of an aldehyde. For example in U. S. Patent p #1378229 naphthalene sulphonic acid is 0011- 128 grams of naphthalene is heated at 130 C. densed with an insoluble naphthalene lrvdrocarwith 128 grams of sulphuric acid (98%) until bon by means of formaldehyde. In this way on water soluble. The temperature is dropped and 5 increased combining weight of the tanning ma- 75 cc. water added, then 48 grams salicylic acid, terial is secured, giving a product in many cases and the temperature adjusted to 85 C. while '73 intermediate in tanning properties between those grams formaldehyde (37%) is run in slowly. made by condensing a sulphonated hydrocarbon Temperature is raised to 100 C. and maintained and sulphonating acondensed hydrocarbon. at this point until satisfactory condensation is $0 By an extension of this type of reaction to a achieved. The mixture is diluted and the ex- 3 large number of materials we have now discovered cess of mineral acid neutralized by soda ash. that by suitable selection of the unsulphonated This solution may be used directly in tanning. material new products may be secured which have Example 2 quite outstanding tanning properties. Of the materials tried we have found that salicylic acid 54 grams of p-crescl is heated with '75 grams 35 is by far the best for use in this connection, of sulphuric acid (98%) for one hour at 75 C. though others such as parahydroxybenzoic acid, To this is added 38 cc. of water, 13.8 grams of parachlorphenol, and the like give good, though salicylic acid and so grams oi formaldehyde not surprisingly good results. I (37%.). The condensation mixture is heated at 419 We are aware that salicylic acid has been 75 C.ror 2% hours. Then the productisdiluted 0 utilized previously in the preparation of tanning and treated with enough alkali to neutralize the materials. For example in U. S. Patent excess mineral acid. The solution may be used #1344350 2. process is described for sulphonatdirectly for tanning. ing salicylic acid and condensing by means of Example 3 formaldehyde. Further in German Patent #512,405 it has been proposed to condense saligrams of crystalline paratertiary amylcylic acid with formaldehyde in an alkaline mephenol is heated with 47.5 grams of sulphuric dium then to acidity and condense with resoracid (66 B.) for two hours at 90-95 C. To this cinol. It has also been suggested in condensations is slowly added 22 cc. of water, 8 grams oi salicylic 50 where urea is used in conjunction with phenol acid and 25 grams of formaldehyde (3'7-8%). sulfonic acid and formaldehyde, that hydroxy- The condensation is continued for four hours at carboxylic acids be also incorporated in the mix- 85 C. The brown, viscous product is diluted and ture, German Patent #539,474. treated with enough alkali to remove the excess We now find however that by the addition of mineral acid. The solution may be used directly relatively small amounts of salicylic acid to arofor tanning. I 55 ceding examples.

Example 4 I 51.5 gramsoi diisobutylphenol is heated wi 38 grams of sulphuric acid (98%) for one hour at 75 C. To this is added. 18 cc. of water, 6.9 grams of salicylic acid and 20 grams of formaldehyde (37%). The product is heated at C. for four hours and then finished as in the. pre- Example 5 228 grams of d-f-dihydrcxydiphenyldimethyh methane is heated with 300 grams sulphuric acid (98%) at 65-70? C. i'or four hours, or until water solubility is obtained. 250 cc. water is now added.

then 69 grams salicylic acid and temperature held at 50-55 C. while 97 grams of formaldehyde (37%) is run in. Heating is continued for live hours at 60-85 C., then the mixture diluted and the excess of mineral acid neutralized by addition of alkali. This solution may be used directly in 7 Example 6 86 grams of tetralin is heated with 75 grams of 98% sulphuric acid for 2 hours at C. To this is added 38 cc. of water, 13.8 grams of salicylie acid and 40 grams of formaldehyde. The condensation and flnal preparation of the solution is similar to that in the preceding examples. A small amount of insoluble material which forms is removed by treating with charcoal and filtering. The filtrate may be used directly in tanning.

Example 7 56 grams of carbazole is heated with 100 grams of 98% sulphuric acid for 1 hour at 92 C. To this is added 48 cc. of water, 9.2 grams of salicylic acid, and 27 grams of 37% formaldehyde. The condensation and subsequent treatment is the same as given in Example 3.

E'sample 8 48 grams of p-naphthol is sulphonated with 50 grams of 98% sulphuric acid for 1 hour at 75 C. To this is added 24 cc. of water, 9.2 grams of salicylic acid and 27 grams of formaldehyde. The method of condensation and subsequent processing is the same as in Example 2.

Example 9 85 grams oi o-phenylphenol is heated with 75 grams of'98% sulphuric acid for 1 hour at 75 C. To this is added 36 cc. of water, 13.8 grams of salicylic acid, and 40 grams of 37% formaldehyde. The rest 'of the procedure is the same as in Example 2.

Example 10 Example 11 47 grams of phenol is sulpiionated as in the preceding example. To this is added 36 cc. of water, 13.8 grams of salicylic acid and 36 grams of n-butyraldehyde. The condensation conditions are the same as in the preceding example.

Example 12 47 grams of-phenoi is sulphonated as in Example 10. To this is addei'ss cc. of water, 13.8

grams of salicylic-acid and 53 grams of benzaldebe used directly in tanning While these represent the preferred method of working, it is also posnble in some cases to carry out the,- reaetion by first condensing the aromatic sulphonicacid with formaldehyde, then adding salicylic acid and more formaldehyde and condensing till a water soluble product is obtained.

As an example 128 and heated at 130 C. with 128 grams sulphuric acid 100% until water soluble. The mixture is cooled, diluted with 80 grams water then 60 grams of aqueous formaldehyde 37% solution added. Heating is continued at 90 C. until condensation is complete. The mixture is diluted to 426 grams, added, and 40 grams then 55 grams salicylic acid more formaldehyde 37% solution. Heating is continued at 90 C. until the mixture is 'tvater soluble, then it is diluted, and the excess of mineral acid neutralized. The solution may be used directly in tanning. I

The amounts of the-reactants may be varied to a considerable extent, though each case there is a range of conditions which will give the best results. For instance in Example 1, for 1 mol. of naphthalene sulphonic acid from 0.2 to 0.4 mol. of salicylic acid. and fromv 0.7 to 0.9 mol. of formaldehyde were found to give the most satisfactory results. Again in Examples 2. 3, and 4 for 1 mol. of sulphonated alkyl substituted phenol, the best amounts of salicylic acid were found to be from 0.2 and 0.5 mol., and of formaldehyde from 0.7 to is mols. In Example 5, for 1 mol. of sulphonated 4-4'-dihydroxy diphenyl dimethylmethane, it was found best to use from nage, or they may be used to bleach and im-.

prove the feel of completely tanned vegetable leather. Another method is to use them as a supplementary tannage for skins treated with aldehydes, when full leather of very light color is secured. Finally in conjunction with chrome tannage they serve as filling agents, giving mellow leather of very light color. particularly when used towards the end of or at the conclusion of a regular chrome tannage.

The actual details of applications in these tannages will readily suggest themselves to one skilled in the art.

It is understood that deviations from theabove are possible without departing from the spirit grams naphthalene is taken soi of the invention, the scope of which is to be limited only by the following claims. No modifications claimed to the exclusion of others.

We claim:

1. Water soluble synthetic resinous tanning material consisting of a condensation product of an aldehyde, an aromatic sulphonic acid and one of the group consisting of salicylic, parahydroxybenzoic acids and parachlorphenol.

2. Water soluble synthetic resinous tanning material consisting of a condensation product of an aldehyde, an aromatic sulphonic acid and salicylic acid.

3. Water Soluble synthetic resinous tanning material consisting of a condensation product oi an aldehyde, 9. hydroxy aromatic sulphonic acid and salicylic acid.

4. Water soluble synthetic resinous tanning material consisting of a condensation product of formaldehyde, an aromatic sulphonic acid and salicylic acid.

5. Water solulfle synthetic resinous tanning material consisting of a condensation product of formaldehyde, a hydroxy aromatic sulphonic acid and salicylic acid.

6. Water soluble synthetic resinous tanning material consisting of a condensation product'of formaldehyde, a naphthalene sulphonic acid and salicylic acid. 7. Water soluble synthetic resinous tanning material consisting of a condensation product of formaldehyde, sulphonated alkyl-substituted phenols and salicylic acid.

8. Water soluble synthetic resinous tanning material consisting of a condensation product of formaldehyde, a tertiary amyl phenol sulphonic acid and salicylic acid.

9. Water soluble synthetic resinous tanning material consisting of a condensation product of formaldehyde, a diphenyloldimethyl methane disulphonic acid and salicylic acid.

10. Water soluble synthetic resinous tanning material consisting of a condensation product of formaldehyde, a naphthalene sulphonic acid and salicylic acid, where the reactants have the molecular ratio-4dr 1 mol. of naphthalene sulphonic acid, from 0.2-0.4 mol. salicylic acid and 0.7-0.9 mol. formaldehyde.

11. Water soluble synthetic resinous tanning material consisting of a condensation product of formaldehyde, a sulphonated allwl-substituted phenol and salicylic acid, where the reactants have the molecular ratio-for 1 mol. of sulphonated alkyl-substituted phenol, from 0.1-0.5 mol. salicylic acid and 0.7-1.4 mols formaldehyde.

12. Water soluble synthetic resinous tanning material consisting of a condensation product of formaldehyde, a tertiary amyl phenol sulphonic acid and salicylic acid, where the reactants have the molecular ratio-for 1 mol. of tertiary amyl phenol sulphonic acid, from 0.1-0.5 mol. salicylic acid, and 0.7-1.4 mols formaldehyde.

13. Water soluble synthetic resinous tanning material consisting of a condensation product of formaldehyde, a sulphonated alkyl-substituted phenol and salicylic acid, where the reactants have the molecular ratio-for 1 mol. of sulpho- -nated 4-4'-dihydroxy diphenyl dimethylmethane,

0.1-0.5 mol. salicylic acid and 0.7-1.4 mols formaldehyde.

WILLIAM F. HESTER. HARRY R. RATERINK. IAN C. SOMERVJILE. 

